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(11) | EP 4 435 318 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | ILLUMINATION DEVICE FOR A VEHICLE |
| (57) Illumination device (10) for a vehicle headlamp, the illumination device comprising: - at least one light guide (100) comprising a light input section (110) and a light output section (120), - a light radiation body (200) comprising a free surface (220), wherein the light coupling out of the at least one light guide (100) can be coupled into the light radiation body (200) via the free surface (220), wherein light from at least one light source (50) can be radiated in front of the illumination device (10) via the light radiation body (200), wherein the illumination device (10) comprises a bundling device (300) configured to bundle and direct the light, which is coupled out from the light output section (120) of the at least one light guide (100), onto the free surface (220) of the light radiation body (200), so that light which is coupled out of the light output section (120) of the at least one light guide (100) and would not reach the free surface (220) due to a smaller width (W) of the free surface (220) compared to a diameter (D) of the light output section (120) of the at least one light guide (100), is deflected onto the free surface (220). |
[0001] The invention relates to an illumination device for a vehicle headlamp, the illumination device comprising:
- at least one light guide comprising a light input section and a light output section,
wherein the light input section is configured to input light of at least one light
source into the light guide, wherein the light output section is configured to output
light out of the light guide,
and wherein the light output section of the at least one light guide follows a first extension line, wherein the light output section in a cross-section orthogonal to the first extension line substantially corresponds to a circle with a diameter, - a light radiation body comprising an end region having a free surface, wherein the
light coupling out of the light output section of the at least one light guide can
be coupled into the light radiation body via the free surface, wherein the light radiation
body further comprises a light radiation surface configured to radiate light coupled
into the light radiation body via the free surface out of the light radiation body
in front of the illumination device,
wherein the free surface follows a second extension line substantially parallel to the first extension line, wherein the free surface in a cross-section orthogonal to the second extension line having a width, wherein the width of the free surface is smaller than the diameter of the light output section of the at least one light guide unit in cross-sections along the first and second extension lines, - at least one light source for emitting light in the visible wavelength range, wherein the light from the at least one light source can be radiated in front of the illumination device via the light radiation body.
[0002] Further, the invention relates to a vehicle headlamp comprising at least one illumination device according to the invention.
[0003] When emitting light via a light radiation body, light must be coupled into the light radiation body as efficiently as possible and distributed as evenly as possible, i.e. light must be coupled in homogeneously.
[0005] To achieve this object the illumination device the illumination device comprises a bundling device configured to bundle and direct the light, which is coupled out from the light output section of the at least one light guide, onto the free surface of the light radiation body, so that light which is coupled out of the light output section of the at least one light guide and does not reach the free surface due to the smaller width of the free surface compared to the diameter of the light output section of the at least one light guide, is deflected onto the free surface.
[0006] Advantageously, the diameter of the cross sections of the at least one light guide along the first extension line is substantially constant.
[0008] Advantageously, the bundling device is formed as a shell which encloses the light output section of the at least one light guide on the side opposite the free surface and has end portions tapering towards the free surface.
[0009] Advantageously, an inner surface of the bundling device is white or metallized for deflection of light.
[0010] Advantageously, the light guide input section of the at least one light guide comprises a light entry surface and a feed section, wherein the light entry surface and the subsequent feed section are configured to couple light of the at least one light source into the light guide and to the light output section of the light guide, wherein light fed into the light guide emerges via a light exit region of the light output section by means of coupling-out elements arranged on the light output section.
[0011] In particular, the feed section of light guides generally serves to mix the light in order to achieve homogeneous light decoupling from the beginning of the viewing area or the light exit surface of a light guide, whereby the light is not decoupled from the feed section and therefore generally has no decoupling elements.
[0012] Advantageously, the at least one light guide comprises a light guide end, which is formed as a cuboid, in particular a rectangular cuboid.
[0014] Advantageously, the at least two light guides are arranged in a way such that the light guide end of one light guide is arranged in the light path of the other light guide after the feed section, in order to enable a homogenous light distribution to the free surface of the light radiation body.
[0015] Advantageously, the bundling device comprises openings through which the at least one light guide is insertable into the bundling device.
[0016] Advantageously, the light radiation body further comprises a light deflection surface opposite to the light radiation surface, wherein the light deflection surface comprises a plurality of light deflection elements configured to deflect light emerging onto the light deflection surface to the light radiation surface.
[0017] Light from the light guide is deflected several times on the inner surface, so the light can be concentrated onto the free surface. Thus, the bundling device acts as a collimator.
[0018] The object of the invention is also achieved by a vehicle headlamp comprising at least one illumination device according to the invention.
Brief description of the drawings
[0019] In the following, in order to further demonstrate the present invention, illustrative and non-restrictive embodiments are discussed, as shown in the drawings, which show:
- Fig. 1
- a perspective view of an example of an illumination device according to the invention, wherein the illumination device comprises two light guides, a radiation body with a free surface, and a bundling device configured to deflect light of the light guides onto the free surface;
- Fig. 2
- a front view of the two light guides of the illumination device of Fig. 1;
- Fig. 3
- a cross-sectional view of the illumination device of Fig. 1 along the line A-A;
- Fig. 4
- a perspective view of the arrangement of the two light guides to each other, where an end section of one light guide is in the light path of the other light guide in front of a feed section of this light guide; and
- Fig. 5
- a back view of the illumination device of Fig. 1.
[0020] Fig. 1 shows illumination device 10 for a vehicle headlamp, the illumination device in the shown example in the figures comprises two light guides 100 comprising a light input section 110 and a light output section 120, wherein the light input section 110 is configured to input light of at least one light source 50 into the light guide 100, wherein the light output section 120 is configured to output light out of the light guide 100. The two light guides 100 are better shown in Fig. 2.
[0021] The light output section 120 of the two light guides 100 follows a first extension line EL1, which is shown in Fig. 1 and Fig. 3, wherein the light output section 120 in a cross-section orthogonal to the first extension line EL1 substantially corresponds to a circle with a diameter D, which is depicted best in Fig. 3 which shows a cross-sectional A-A view of Fig. 1. The diameter D of the cross sections of the two light guides 100 along the first extension line EL1 is substantially constant. In the shown example, the diameter D of the two light guides 100 is at least 4 mm.
[0022] As can be seen in Fig. 2, the light guide input section 110 of the two light guides 100 comprises a light entry surface 110a and a feed section 110b, wherein the light entry surface 110a and the subsequent feed section 110b are configured to couple light of the at least one light source 50 into the light guides 100 and to the light output section 120 of the light guides 100, wherein light fed into the light guide 100 emerges via a light exit region of the light output section 120 by means of coupling-out elements arranged on the light output section 120.
[0023] Further, the illumination device 10 comprises a light radiation body 200 comprising an end region 210 having a free surface 220, wherein the light coupling out of the light output section 120 of the two light guides 100 can be coupled into the light radiation body 200 via the free surface 220.
[0024] The light radiation body 200 further comprises a light radiation surface 230 configured to radiate light coupled into the light radiation body 200 via the free surface 220 out of the light radiation body 200 in front of the illumination device 10.
[0025] The free surface 220 follows a second extension line EL2 substantially parallel to the first extension line EL1, wherein the free surface 220 in a cross-section orthogonal to the second extension line EL2 having a width W, wherein the width W of the free surface 220 is smaller than the diameter D of the light output section 120 of the at least one light guide 100 seen in cross-sections along the first and second extension lines EL1, EL2.
[0026] The at least one light source 50 for each light guide 100 is configured to emit light in the visible wavelength range, wherein the light from the at least one light source 50 can be radiated in front of the illumination device 10 via the light radiation body 200.
[0027] The light radiation body 200 further comprises a light deflection surface opposite to the light radiation surface 230, wherein the light deflection surface comprises a plurality of light deflection elements (not shown in the figures) configured to deflect light emerging onto the light deflection surface to the light radiation surface 230.
[0028] The illumination device 10 further comprises a bundling device 300 configured to bundle and direct the light, which is coupled out from the light output section 120 of the two light guides 100, onto the free surface 220 of the light radiation body 200, so that light which is coupled out of the light output section 120 of the two light guides 100 and would not reach the free surface 220 due to the smaller width W of the free surface 220 compared to the diameter D of the light output section 120 of the at least one light guide 100, is deflected onto the free surface 220.
[0029] As can be seen for example in Fig. 1 and Fig. 2, the bundling device 300 is formed as a shell which encloses the light output section 120 of the at least one light guide 100 on the side opposite the free surface 220 and has end portions 320 tapering towards the free surface 220.
[0030] Further, the bundling device 300 comprises openings 310 (seen in Fig. 1) through which the light guides 100 are insertable into the bundling device 300.
[0031] In the shown example in the figures, an inner surface of the bundling device 300 is metallized for deflection of light.
[0032] As can be seen in Fig. 4, one light guide 100 comprises a light guide end 130, which is formed as a cuboid, in particular a rectangular cuboid.
[0033] The at least two light guides 100 are arranged in a way such that the light guide end 130 of the one light guide 100 is arranged in the light path of the other light guide 100 after the feed section 110b, in order to enable a homogenous light distribution to the free surface 220 of the light radiation body 200.
LIST OF REFERENCE SIGNS
[0035]
| Illumination device | 10 |
| Light source | 50 |
| Light guide | 100 |
| Light input section | 110 |
| Light entry surface | 110a |
| Feed section | 110b |
| Light output section | 120 |
| Light guide end | 130 |
| Light radiation body | 200 |
| End region | 210 |
| Free surface | 220 |
| Light radiation surface | 230 |
| Bundling device | 300 |
| Opening | 310 |
| End portions | 320 |
| First extension line | EL1 |
| Second extension line | EL2 |
| Diameter | D |
| Width | W |
1. Illumination device (10) for a vehicle headlamp, the illumination device comprising:
- at least one light guide (100) comprising a light input section (110) and a light
output section (120), wherein the light input section (110) is configured to input
light of at least one light source (50) into the light guide (100), wherein the light
output section (120) is configured to output light out of the light guide (100),
and wherein the light output section (120) of the at least one light guide (100) follows
a first extension line (EL1), wherein the light output section (120) in a cross-section
orthogonal to the first extension line (EL1) substantially corresponds to a circle
with a diameter (D),
- a light radiation body (200) comprising an end region (210) having a free surface
(220), wherein the light coupling out of the light output section (120) of the at
least one light guide (100) can be coupled into the light radiation body (200) via
the free surface (220), wherein the light radiation body (200) further comprises a
light radiation surface (230) configured to radiate light coupled into the light radiation
body (200) via the free surface (220) out of the light radiation body (200) in front
of the illumination device (10),
wherein the free surface (220) follows a second extension line (EL2) substantially
parallel to the first extension line (EL1), wherein the free surface (220) in a cross-section
orthogonal to the second extension line (EL2) having a width (W), wherein the width
(W) of the free surface (220) is smaller than the diameter (D) of the light output
section (120) of the at least one light guide (100) seen in cross-sections along the
first and second extension lines (EL1, EL2),
- at least one light source (50) for emitting light in the visible wavelength range,
wherein the light from the at least one light source (50) can be radiated in front
of the illumination device (10) via the light radiation body (200),
characterized in that
the illumination device (10) comprises a bundling device (300) configured to bundle
and direct the light, which is coupled out from the light output section (120) of
the at least one light guide (100), onto the free surface (220) of the light radiation
body (200), so that light which is coupled out of the light output section (120) of
the at least one light guide (100) and would not reach the free surface (220) due
to the smaller width (W) of the free surface (220) compared to the diameter (D) of
the light output section (120) of the at least one light guide (100), is deflected
onto the free surface (220).
2. Illumination device according to claim 1, wherein the diameter (D) of the cross sections of the at least one light guide (100) along
the first extension line (EL1) is substantially constant.
3. Illumination device according to claim 1 or 2, wherein the diameter (D) of the at least one light guide (100) is at least 4 mm.
4. Illumination device according to one of claims 1 to 3, wherein the bundling device (300) is formed as a shell which encloses the light output section
(120) of the at least one light guide (100) on the side opposite the free surface
(220) and has end portions (320) tapering towards the free surface (220).
5. Illumination device according to claim 4, wherein an inner surface of the bundling device (300) is white or metallized for deflection
of light.
6. Illumination device according to any of claims 1 to 5, wherein the light guide input section (110) of the at least one light guide (100) comprises
a light entry surface (110a) and a feed section (110b), wherein the light entry surface
(110a) and the subsequent feed section (110b) are configured to couple light of the
at least one light source (50) into the light guide (100) and to the light output
section (120) of the light guide (100), wherein light fed into the light guide (100)
emerges via a light exit region of the light output section (120) by means of coupling-out
elements arranged on the light output section (120).
7. Illumination device according to any of claims 1 to 6, wherein the at least one light guide (100) comprises a light guide end (130), which is formed
as a cuboid, in particular a rectangular cuboid.
8. Illumination device according to any one of claims 1 to 7, wherein the illumination device (10) comprises at least two light guides (100).
9. Illumination device according to claim 8, wherein the at least two light guides (100) are arranged in a way such that the light guide
end (130) of one light guide (100) is arranged in the light path of the other light
guide (100) after the feed section (110b), in order to enable a homogenous light distribution
to the free surface (220) of the light radiation body (200).
10. Illumination device according to any one of claims 1 to 9, wherein the bundling device (300) comprises openings (310) through which the at least one
light guide (100) is insertable into the bundling device (300).
11. Illumination device according to any one of claims 1 to 10, wherein the light radiation body (200) further comprises a light deflection surface opposite
to the light radiation surface (230), wherein the light deflection surface comprises
a plurality of light deflection elements configured to deflect light emerging onto
the light deflection surface to the light radiation surface (230).
12. Vehicle headlamp comprising at least one illumination device (10) according to any
of claims 1 to 11.